A program of coordinated studies is designed to investigate child development in families with and without affective disorders. The program has four interrelated components. One is the delineation of attributes of pathological and normal rearing environments. Maternal behavior and parental child interactional patterns are investigated with regard to affective qualities (in content, form, and function), cognitive properties, and control or regulatory aspects (also in content, form and function). The second component is the assessment of children in terms of their cognitive, affective, and interpersonal skills and dysfunctions. The third objective is to treat the study as an offspring study, comparing diagnoses of children with diagnoses of parents. The fourth and major component is the investigation of processes of transmission of adaptive and maladaptive behavior patterns in children. This entails study of the multiple pathways of influence and the varied repertoires of coping in rearing and being reared. By using direct observation over time, this study brings to "offspring" research some of the data necessary to understand the kinds of learning experiences out of which behavior develops, in interaction with predispositions in the child.